On the trail of new developments

On the trail of new developments: Is chemical recycling the solution for previously non-recyclable plastics?

Creating networks, getting to know new topics every day, overcoming boundaries: For Nadya Bendig, development engineer at REHAU, this is everyday work. She is part of REHAU's internal materials development and is always on the lookout for new ways to increase the proportion of recycled material in our products. As a rule, so-called mechanical recycling is used - plastic waste is washed, sorted and processed into granulate, which is then used to manufacture new products. But what options are there when this method reaches its limits? This is the question Nadya and her team are addressing. Among other things, they are investigating the possibilities offered by chemical recycling in such cases. Nadya explains this in an interview.

You are part of RIT, the "Research, Innovation & Technology" department at REHAU. How can we imagine your work?

RIT is a central research and development unit of the REHAU Group. We research new approaches from science and technology in order to support our divisions in the further development of their products. I am part of the specialization area recycling. Our focus is on helping our divisions select suitable recycling materials for use in existing products.

What exactly is your job?

I deal with the screening and analysis of recycled materials and look for new applications to bring them into more and more REHAU products. My tasks include ensuring that the quality and availability of raw materials meet our requirements. This also includes building partnerships along the recycling value chain from procurement to processing to the product. I also support my colleagues in our product management team in designing new products. These should preferably be made from recycled materials. At the same time, they should be easily recyclable at the end of their life cycle in order to close material cycles and reduce CO₂ emissions. Another important area of activity is cooperation with partners to develop new recycling technologies for plastics that are difficult to recycle.

Nadya Bendig

So conventional recycling is not suitable for all plastics?

No. So far, mechanical recycling has been used predominantly. For this, old raw materials and used products are taken back, cleaned, processed and then used to manufacture new products. However, this is not a solution for all types of plastics. Reasons for this are, for example, that a material cannot be thermally melted or impurities such as printing have a negative impact on the quality of the mechanically recycled material.

What options are there in this case?

For such waste streams, chemical recycling, for example, offers an exciting approach. In this process, plastic waste is broken down into its original building blocks by changing its chemical structure. These building blocks can be used to manufacture new plastics, but also products such as chemicals or fuels. Thus, chemical recycling complements mechanical recycling processes by enabling the reuse of plastics that otherwise could not have been reused.

Why is this method not already more widely used?

This recycling process is still very new. It has many advantages, but at this stage it also poses challenges. This is because chemical recycling requires complex and technologically sophisticated processes. In addition, it has a poorer carbon footprint than mechanical recycling due to its higher energy requirements. There is also often no final solution for the treatment and disposal of potential by-products generated during the process. However, no one can draw a final conclusion about this process at the present time. It is still too early for that. That is normal for a new process: Now that we know it works, it needs to be optimized.

After all, whenever mechanical recycling reaches its limits, chemical recycling is an important alternative for keeping materials in circulation rather than landfilling or incinerating them. Most major raw material producers therefore see great potential in this and are investing extensively in both research and concrete first plants to address precisely the challenges mentioned and to develop environmentally compatible and competitive processes. In partnerships with selected raw material producers, we are therefore already involved in this area and are testing applications in which we have not yet found a solution through mechanical recycling.

Are there examples where chemical recycling is already being used at REHAU?

Basically, when developing new products, we work on creating the design from the very beginning so that the product consists of recycled and recyclable materials and can be returned to the cycle as easily as possible at the end of its life. For existing product lines, we are testing how we can increase the proportion of recycled materials using mechanical recycling. To this end, we are also working on take-back concepts to collect residual quantities and process them further.

What makes me particularly proud is that our efforts are demonstrably bearing fruit. Last year, we already achieved our goal of increasing the proportion of recycled materials in our products to 15 percent compared to 2018. Since we overachieved this target reaching 18 percent globally, we have now set a new goal of 20 percent. Of course, to meet or exceed that again, we need to continue researching new opportunities.

Where mechanical recycling is not possible, we are therefore looking at how we can extend these limits by means of chemical recycling. Together with our colleagues in the divisions and with raw material suppliers, we are working to test the first materials on a pilot scale. This year, for example, we were able to demonstrate with our Building Solutions division that production waste generated in the manufacture of house installation products can be reused through chemical recycling. The waste thus becomes a valuable material for the production of new plastics.

So, would you say chemical recycling is THE solution for non-recyclable plastics?

No. At this point in time, it is not yet THE all-encompassing solution that can be used on a large scale. The process still has too many challenges for that. New products should be thought of and designed to be recyclable right from the start. Different routes should be tested for the existing portfolio, and in turn, for individual use cases, we can look at whether chemical recycling is already a good solution today when mechanical recycling reaches its limits. In any case, we need to do further research to make the process even better and exploit its potential.

Thank you very much for the informative interview!

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